8GB Total. Two 4GB PC3-10600S 204 pin SODIMM DDR3 1333MHz THIS MODULE IS MANUFACTURED BY MICRON, SAMSUNG OR ELPIDA LIFETIME WARRANTY BY MANUFACTURED MAX MEMORY: 32GB SOCKETS 4
COMPATIBLE WITH: Apple iMac "Core i7" 2.8 21.5 -Inch (Mid-2011) Mid-2011 - BTO/CTO - iMac12, 1 - A1311 - 2428